Which of the following species contains minimum number of atoms in XY plane ?

Options

A. `XeF_(5)^(-)`
B. `SF_(6)`
C. `IF_(7)`
D. All

Explanation

To determine which of the given species contains the minimum number of atoms in the XY plane, we will analyze each species one by one.

### Step-by-Step Solution:

1. **Identify the Species**: We have three species to analyze: XCF5^-, SF6, and IF7.

2. **Analyze XCF5^-**:
- X is a noble gas, which has 8 electrons in its outer shell. With an additional negative charge, it has a total of 9 electrons.
- It forms 5 bond pairs with 5 fluorine atoms and has 2 lone pairs.
- The hybridization of XCF5^- is calculated as:
\[ \text{Hybridization} = \text{Number of bond pairs} + \text{Number of lone pairs} = 5 + 2 = 7 \quad (\text{sp}^3\text{d}^3) \]
- The molecular geometry is pentagonal bipyramidal. In this geometry, there are 5 fluorine atoms in the XY plane and 2 lone pairs, which occupy axial positions (above and below the plane).

3. **Analyze SF6**:
- Sulfur has 6 electrons in its outer shell and forms 6 bond pairs with 6 fluorine atoms.
- The hybridization is:
\[ \text{Hybridization} = 6 \quad (\text{sp}^3\text{d}^2) \]
- The molecular geometry is octahedral. In this case, 4 fluorine atoms are in the XY plane (forming a square planar arrangement), while 2 fluorine atoms are positioned above and below the plane.

4. **Analyze IF7**:
- Iodine has 7 electrons in its outer shell and forms 7 bond pairs with 7 fluorine atoms.
- The hybridization is:
\[ \text{Hybridization} = 7 \quad (\text{sp}^3\text{d}^3) \]
- The molecular geometry is also pentagonal bipyramidal. Similar to XCF5^-, there are 5 fluorine atoms in the XY plane, with 2 lone pairs occupying the axial positions.

5. **Count Atoms in the XY Plane**:
- For **XCF5^-**: 5 fluorine atoms (in the plane).
- For **SF6**: 4 fluorine atoms (in the plane).
- For **IF7**: 5 fluorine atoms (in the plane).

6. **Conclusion**: The species with the minimum number of atoms in the XY plane is **SF6**, which has 4 atoms in the XY plane.

### Final Answer:
**SF6** contains the minimum number of atoms in the XY plane.